Dietary and nutritional factors and pancreatic cancer: a case-control study based on direct interviews

Antioxidant intake and pancreatic cancer risk: the Vitamins and Lifestyle (VITAL) Study

BACKGROUND

Oxidative stress causes damage to many components of human cells (ie, proteins, lipids, and DNA) and is involved in carcinogenesis. Nutrients with antioxidant properties may protect against oxidative stress. In this study, the authors examined the intake of antioxidants from diet and supplements in relation to pancreatic cancer risk among participants of the Vitamins and Lifestyle (VITAL) Study.

METHODS

The participants included 77,446 men and women ages 50 to 76 years who were residents of western Washington State and who completed a baseline questionnaire between 2000 and 2002. Participants reported usual diet over the past year and use of supplements over the past 10 years in addition to demographic and lifestyle factors. During a median follow-up of 7.1 years, 184 participants developed pancreatic adenocarcinoma. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for 7 antioxidants: β-carotene, lutein plus zeaxanthin, lycopene, vitamin C, vitamin E, selenium, and zinc.

RESULTS

An inverse association was observed between dietary selenium and the risk of pancreatic cancer (medium vs low intake: HR, 0.58; 95% CI, 0.35-0.94; high vs low intake: HR, 0.44; 95% CI, 0.23-0.85; Ptrend = .01); however, when supplemental and dietary exposures were combined, the association was no longer statistically significant.

CONCLUSIONS

Dietary selenium intake was inversely associated with the risk of pancreatic cancer, and the observed association was attenuated by selenium supplementation.

Intake of fruits and vegetables and risk of pancreatic cancer in a pooled analysis of 14 cohort studies

Fruit and vegetable intake may protect against pancreatic cancer, since fruits and vegetables are rich in potentially cancer-preventive nutrients. Most case-control studies have found inverse associations between fruit and vegetable intake and pancreatic cancer risk, although bias due to reporting error cannot be ruled out. In most prospective studies, inverse associations have been weaker and imprecise because of small numbers of cases. The authors examined fruit and vegetable intake in relation to pancreatic cancer risk in a pooled analysis of 14 prospective studies from North America, Europe, and Australia (study periods between 1980 and 2005). Relative risks and 2-sided 95% confidence intervals were estimated separately for the 14 studies using the Cox proportional hazards model and were then pooled using a random-effects model. Of 862,584 men and women followed for 7-20 years, 2,212 developed pancreatic cancer. The pooled multivariate relative risks of pancreatic cancer per 100-g/day increase in intake were 1.01 (95% confidence interval (CI): 0.99, 1.03) for total fruits and vegetables, 1.01 (95% CI: 0.99, 1.03) for total fruits, and 1.02 (95% CI: 0.99, 1.06) for total vegetables. Associations were similar for men and women separately and across studies. These results suggest that fruit and vegetable intake during adulthood is not associated with a reduced pancreatic cancer risk.

Dietary intake of iron, heme-iron and magnesium and pancreatic cancer risk in the European prospective investigation into cancer and nutrition cohort

Several studies support a protective effect of dietary magnesium against type 2 diabetes, but a harmful effect for iron. As diabetes has been linked to pancreatic cancer, intake of these nutrients may be also associated with this cancer. We examined the association between dietary intake of magnesium, total iron and heme-iron and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. In total, 142,203 men and 334,999 women, recruited between 1992 and 2000, were included. After an average follow-up of 11.3 years, 396 men and 469 women developed exocrine pancreatic cancer. Hazard ratios and 95% confidence intervals (CIs) were obtained using Cox regression stratified by age and center, and adjusted for energy intake, smoking status, height, weight, and self-reported diabetes status. Neither intake of magnesium, total iron nor heme-iron was associated with pancreatic cancer risk. In stratified analyses, a borderline inverse association was observed among overweight men (body mass index, ≥ 25 kg/m(2) ) with magnesium (HR(per 100 mg/day increase) = 0.79, 95% CI = 0.63-1.01) although this was less apparent using calibrated intake. In female smokers, a higher intake of heme-iron was associated with a higher pancreatic cancer risk (HR (per 1 mg/day increase) = 1.38, 95% CI = 1.10-1.74). After calibration, this risk increased significantly to 2.5-fold (95% CI = 1.22-5.28). Overall, dietary magnesium, total iron and heme-iron were not associated with pancreatic cancer risk during the follow-up period. Our observation that heme-iron was associated with increased pancreatic cancer risk in female smokers warrants replication in additional study populations.

Obesity and pancreatic cancer: overview of epidemiologic evidence and biologic mechanisms

In the United States, pancreatic cancer is characterized by a low 5-yr survival rate of approximately 6%, fewer than 10% of patients diagnosed with localized disease and thus candidates for "curative" surgical resection, increasing incidence and few established risk factors. Similar statistics are observed for other industrialized nations. With new evidence to suggest that pancreatic cancer develops over a number of years, markers that can better identify high risk patients and are applicable to earlier diagnosis hold promise for improving these dire statistics. Obesity is one of the few modifiable risk factors that has been associated with increased risk of pancreatic cancer and also is related to increased risk of diabetes, a condition that in turn has been associated with pancreatic cancer development. Given recent data that nearly 70% of United States adults are overweight or obese, a clarification of the complex association between obesity and pancreatic cancer may disclose targets for prevention and intervention to decrease incidence and improve prognosis of this highly fatal disease. An overview of the current epidemiology and hypothesized biological mechanisms involved in the obesity-pancreatic cancer association are presented.

Pancreatic cancer: Helicobacter pylori colonization, N-nitrosamine exposures, and ABO blood group

Thirty years of research with animal models has shown that pancreatic adenocarcinoma is induced by N-nitrosamine carcinogens, which damage DNA through adduct formation. Human risk factors for pancreatic cancer include gastric colonization by Helicobacter pylori, as well as dietary intake of those same N-nitrosamines or of nitrite which forms those N-nitrosamines in the stomach, and cigarette smoking which also contains those N-nitrosamines. Physiologic actions of H. pylori colonization enhance the carcinogenic effect of N-nitrosamines delivered by smoking or dietary sources. This effect is modulated by host inflammatory response to the organism, by various virulence and other properties of the Helicobacter itself, and by host-organism interactions. A recent genome-wide association study identified SNPs within the ABO 9q34 locus as statistically significantly associated with risk of pancreatic cancer. A number of recent and older studies going back 40 yr also support the ABO association. ABO-product antigens are expressed on gastrointestinal epithelium on which H. pylori binds, and ABO genotype is known to be associated with risks of duodenal and gastric ulcer and with risk of gastric cancer, conditions definitively related to Helicobacter colonization. We suspect that ABO genotype/phenotype status influences the behavior of H. pylori which in turn affects gastric and pancreatic secretory function, and these ultimately influence the pancreatic carcinogenicity of dietary- and smoking-related N-nitrosamine exposures, and thus risk of pancreatic cancer. Our study results on the interaction of ABO and H. pylori significantly confirm this hypothesis and together with other existing studies strongly implicate this organism in the disease etiology.

Coffee, tea, and sugar-sweetened carbonated soft drink intake and pancreatic cancer risk: a pooled analysis of 14 cohort studies

BACKGROUND

Coffee has been hypothesized to have pro- and anticarcinogenic properties, whereas tea may contain anticarcinogenic compounds. Studies assessing coffee intake and pancreatic cancer risk have yielded mixed results, whereas findings for tea intake have mostly been null. Sugar-sweetened carbonated soft drink (SSB) intake has been associated with higher circulating levels of insulin, which may promote carcinogenesis. Few prospective studies have examined SSB intake and pancreatic cancer risk; results have been heterogeneous.

METHODS

In this pooled analysis from 14 prospective cohort studies, 2,185 incident pancreatic cancer cases were identified among 853,894 individuals during follow-up. Multivariate (MV) study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and then pooled using a random-effects model.

RESULTS

No statistically significant associations were observed between pancreatic cancer risk and intake of coffee (MVRR = 1.10; 95% CI, 0.81-1.48 comparing ≥900 to <0 g/d; 237g ≈ 8oz), tea (MVRR = 0.96; 95% CI, 0.78-1.16 comparing ≥400 to 0 g/d; 237g ≈ 8oz), or SSB (MVRR = 1.19; 95% CI, 0.98-1.46 comparing ≥250 to 0 g/d; 355g ≈ 12oz; P value, test for between-studies heterogeneity > 0.05). These associations were consistent across levels of sex, smoking status, and body mass index. When modeled as a continuous variable, a positive association was evident for SSB (MVRR = 1.06; 95% CI, 1.02-1.12).

CONCLUSION AND IMPACT

Overall, no associations were observed for intakes of coffee or tea during adulthood and pancreatic cancer risk. Although we were only able to examine modest intake of SSB, there was a suggestive, modest positive association for risk of pancreatic cancer for intakes of SSB.

Folate intake and risk of pancreatic cancer: pooled analysis of prospective cohort studies

BACKGROUND

Epidemiological studies evaluating the association between folate intake and risk of pancreatic cancer have produced inconsistent results. The statistical power to examine this association has been limited in previous studies partly because of small sample size and limited range of folate intake in some studies.

METHODS

We analyzed primary data from 14 prospective cohort studies that included 319,716 men and 542,948 women to assess the association between folate intake and risk of pancreatic cancer. Folate intake was assessed through a validated food-frequency questionnaire at baseline in each study. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random effects model. All statistical tests were two-sided.

RESULTS

During 7-20 years of follow-up across studies, 2195 pancreatic cancers were identified. No association was observed between folate intake and risk of pancreatic cancer in men and women (highest vs lowest quintile: dietary folate intake, pooled multivariable RR = 1.06, 95% CI = 0.90 to 1.25, P(trend) = .47; total folate intake [dietary folate and supplemental folic acid], pooled multivariable RR = 0.96, 95% CI = 0.80 to 1.16, P(trend) = .90). No between-study heterogeneity was observed (for dietary folate, P(heterogeneity) = .15; for total folate, P(heterogeneity) = .22).

CONCLUSION

Folate intake was not associated with overall risk of pancreatic cancer in this large pooled analysis.

Main dietary compounds and pancreatic cancer risk. The quantitative analysis of case-control and cohort studies

OBJECTIVE

Estimation of the role of main dietary compounds in the risk of developing pancreatic cancer.

RESEARCH METHODS AND PROCEDURES

Literature published till 2010 was reviewed and selected for further analysis. The used terms were: red meat, minced meat, ham, bacon, sausages, white meat, poultry, vegetables, fish, eggs, fruits, lifestyle, diet, pancreatic cancer and pancreatic neoplasm. The collected data were meta-analysed with calculation of combined relative risk and 95% confidence interval as well as studies heterogeneity.

RESULTS

A meta-analysis of 11 case-control studies indicates that red meat ingestion elevates pancreatic cancer risk by 48% (95% CI=1.25-1.76). The vegetables and fruit reduce the risk by 38% (95% CI=0.54-0.73) and 29% (95% CI=0.59-0.84), respectively. The pooled analyses of 10 cohort studies do not show significant relations between main dietary compound ingestion and pancreatic cancer risk.

CONCLUSION

The red meat intake is associated with elevated risk of pancreatic cancer in contrast to vegetables and fruit ingestion. The ingestion of red meat, vegetables and fruit in cohort studies was not influenced on pancreatic cancer risk. The role of fish, poultry and eggs was not significant in both case-control and cohort studies, thus further studies were needed.

Fruit and vegetable consumption is inversely associated with having pancreatic cancer

OBJECTIVE

Studies on fruit, vegetable, fiber, and grain consumption and pancreatic cancer risk are inconclusive. We used a clinic-based case-control study specifically designed to address limitations of both cohort and case-control studies to examine the relationship.

METHODS

Participants were excluded who reported changing their diet within 5 years prior to study entry. And 384 rapidly ascertained cases and 983 controls (frequency matched on age (±5 years), race, sex, and residence) completed epidemiologic surveys and 144-item food frequency questionnaires. Odds ratios (OR) and 95% confidence intervals were calculated using logistic regression adjusted for age, sex, smoking, body mass index, energy intake, and alcohol consumption.

RESULTS

Comparing highest to lowest quintiles, we observed significant inverse associations (OR < 0.8) with significant trends (p (trend) < 0.05) for citrus, melon, and berries, other fruits, dark green vegetables, deep yellow vegetables, tomato, other vegetables, dry bean and pea, insoluble fiber, soluble fiber, whole grains, and orange/grapefruit juice, and an increased association with non-whole grains. Results were similar after adjusting for diabetes or total sugar intake.

CONCLUSIONS

We provide evidence that lower consumption of fruits, vegetables, whole grains, and fiber is associated with having pancreatic cancer. This may have a role in developing prevention strategies.

Dietary insulin load, dietary insulin index, and risk of pancreatic cancer

BACKGROUND

Although hyperinsulinemia and insulin resistance have been hypothesized to be involved in pancreatic carcinogenesis, studies that have examined glycemic load or individual dietary components that influence glucose concentrations yielded inconclusive results.

OBJECTIVE

Our objective was to investigate whether dietary insulin load and dietary insulin index are associated with the risk of pancreatic cancer.

DESIGN

We prospectively followed 86,740 women and 46,147 men who were free of cancer and diabetes at baseline in the Nurses' Health Study and the Health Professionals Follow-Up Study. During ≤26 y of follow-up, 691 pancreatic cancer cases were documented. Dietary insulin load was calculated as a function of the food insulin index, and the energy content of individual foods was reported on food-frequency questionnaires. The dietary insulin index was calculated by dividing the dietary insulin load by the total energy intake.

RESULTS

Dietary insulin load and dietary insulin index were not associated with the overall risk of pancreatic cancer. In a comparison of the highest with the lowest quintiles, the pooled multivariate RRs of pancreatic cancer were 1.05 (95% CI: 0.82, 1.34) for dietary insulin load and 0.96 (95% CI: 0.75, 1.23) for dietary insulin index. In individuals with an elevated BMI (in kg/m(2); ≥27.5) or with low physical activity, a high insulin load was associated with small, nonsignificant increases in the risk of pancreatic cancer; in a comparison of the highest with the lowest tertile of intake, the positive association became more apparent in those who were both overweight and inactive (RR: 2.03; 95% CI: 1.05, 3.93; P-trend = 0.04).

CONCLUSIONS

A diet that induces an elevated postprandial insulin response does not influence the overall risk of pancreatic cancer. However, a diet with a high insulin load may increase the risk in individuals with a preexisting state of insulin resistance.

Pancreatic cancer and exposure to dietary nitrate and nitrite in the NIH-AARP Diet and Health Study

Nitrate and nitrite are precursors of N-nitroso compounds, which induce tumors of the pancreas in animals. The authors evaluated the relation of dietary nitrate and nitrite to pancreatic cancer risk in the NIH-AARP Diet and Health Study. Nitrate and nitrite intakes were assessed at baseline using a 124-item food frequency questionnaire. During approximately 10 years of follow-up between 1995 and 2006, 1,728 incident pancreatic cancer cases were identified. There was no association between total nitrate or nitrite intake and pancreatic cancer in men or women. However, men in the highest quintile of summed nitrate/nitrite intake from processed meat had a nonsignificantly elevated risk of pancreatic cancer (hazard ratio = 1.18, 95% confidence interval: 0.95, 1.47; P-trend = 0.11). The authors observed a stronger increase in risk among men for nitrate/nitrite intake from processed meat at ages 12-13 years (highest quintile vs. lowest: hazard ratio = 1.32, 95% confidence interval: 0.99, 1.76; P-trend = 0.11), though the relation did not achieve statistical significance. The authors found no associations between adult or adolescent nitrate or nitrite intake from processed meats and pancreatic cancer among women. These results provide modest evidence that processed meat sources of dietary nitrate and nitrite may be associated with pancreatic cancer among men and provide no support for the hypothesis in women.

Citrus flavonoids luteolin, apigenin, and quercetin inhibit glycogen synthase kinase-3β enzymatic activity by lowering the interaction energy within the binding cavity

Pancreatic cancer studies have shown that inhibition of glycogen synthase kinase-3β (GSK-3β) leads to decreased cancer cell proliferation and survival by abrogating nuclear factor κB (NFκB) activity. In this investigation, various citrus compounds, including flavonoids, phenolic acids, and limonoids, were individually investigated for their inhibitory effects on GSK-3β by using a luminescence assay. Of the 22 citrus compounds tested, the flavonoids luteolin, apigenin, and quercetin had the highest inhibitory effects on GSK-3β, with 50% inhibitory values of 1.5, 1.9, and 2.0 μM, respectively. Molecular dockings were then performed to determine the potential interactions of each citrus flavonoid with GSK-3β. Luteolin, apigenin, and quercetin were predicted to fit within the binding pocket of GSK-3β with low interaction energies (-76.4, -76.1, and -84.6 kcal·mol(-1), respectively) and low complex energies (-718.1, -688.1, and -719.7 kcal·mol(-1), respectively). Our results indicate that several citrus flavonoids inhibit GSK-3β activity and suggest that these have potential to suppress the growth of pancreatic tumors.

Preoperative computed tomography measurements of pancreatic steatosis and visceral fat: prognostic markers for dissemination and lethality of pancreatic adenocarcinoma

BACKGROUND

Increased visceral fat and pancreatic steatosis promote lymphatic metastases and decreased survival in patients with pancreatic adenocarcinoma after pancreatoduodenectomy (PD).

OBJECTIVES

We aim to determine the utility of preoperative computed tomography (CT) measurements of pancreatic steatosis and visceral fat as prognostic indicators in patients with pancreatic adenocarcinoma.

METHODS

High-resolution CT scans of 42 patients undergoing PD for pancreatic adenocarcinoma were reviewed. Attenuation in CT of the pancreas, liver and spleen were measured in Hounsfield units and scored by two blinded investigators. Perirenal adipose tissue was measured in mm.

RESULTS

Lymphatic metastases were present in 57% of patients. Age, gender, tumour size and margin status were similar in patients with and without nodal metastases. Node-positive patients had increased visceral but not subcutaneous fat pads compared with node-negative patients and decreased CT attenuation of the pancreatic body and tail and liver. Node-positive patients stratified by visceral adiposity (≥10 mm vs. <10 mm) demonstrated poorer survival (7 ± 1 months vs. 16 ± 2 months; P < 0.01).

CONCLUSIONS

In resected pancreatic adenocarcinoma, increased pancreatic steatosis and increased visceral fat stores are associated with lymphatic metastases. Furthermore, increased visceral fat is associated with abbreviated survival in patients with lymphatic metastases. Hence, increased visceral fat may be a causative factor of abbreviated survival and serves a prognostic role in patients with pancreatic malignancies.

Rapamycin partially mimics the anticancer effects of calorie restriction in a murine model of pancreatic cancer

Etiologic factors for pancreatic cancer, the 4th deadliest malignant neoplasm in the United States, include obesity and abnormal glucose metabolism. Calorie restriction (CR) and rapamycin each affect energy metabolism and cell survival pathways via inhibition of mammalian target of rapamycin (mTOR) signaling. By using a Panc02 murine pancreatic cancer cell transplant model in 45 male C57BL/6 mice, we tested the hypothesis that rapamycin mimics the effects of CR on pancreatic tumor growth. A chronic regimen of CR, relative to an ad libitum-fed control diet, produced global metabolic effects such as reduced body weight (20.6 ± 1.6 g vs. 29.3 ± 2.3 g; P < 0.0001), improved glucose responsiveness, and decreased circulating levels of insulin-like growth factor (IGF)-1 (126 ± 8 ng/mL vs. 199 ± 11 ng/mL; P = 0.0006) and leptin (1.14 ± 0.2 ng/mL vs. 5.05 ± 1.2 ng/mL; P = 0.01). In contrast, rapamycin treatment (2.5 mg/kg intraperitoneal every other day, initiated in mice following 20 weeks of ad libitum control diet consumption), relative to control diet, produced no significant change in body weight, IGF-1 or leptin levels, but decreased glucose responsiveness. Pancreatic tumor volume was significantly reduced in the CR group (221 ± 107 mm(3); P < 0.001) and, to a lesser extent, the rapamycin group (374 ± 206 mm(3); P = 0.04) relative to controls (550 ± 147 mm(3)), and this differential inhibition correlated with expression of the proliferation marker Ki-67. Both CR and rapamycin decreased phosphorylation of mTOR, p70/S6K, and S6 ribosomal protein, but only CR decreased phosphorylation of Akt, GSK-3β, extracellular signal regulated kinase/mitogen-activated protein kinase, and STAT3(TYR705). These findings suggest that rapamycin partially mimics the anticancer effects of CR on tumor growth in a murine model of pancreatic cancer.

Intake of vegetables, fruits, carotenoids and vitamins C and E and pancreatic cancer risk in The Netherlands Cohort Study

Epidemiological data investigating the relation between fruit and vegetable consumption and pancreatic cancer risk have shown inconsistent results so far. Most case-control studies observed an inverse association with total fruit and vegetable consumption, whereas results from most cohort studies have largely been null. We examined prospectively the relation between pancreatic cancer risk and intake of vegetables, fruits, carotenoids and vitamins C and E. The Netherlands Cohort Study consisted of 120,852 men and women who completed a questionnaire at baseline in 1986, including a validated 150-item food-frequency questionnaire. After 16.3 years of follow-up, 423 cases were available for analysis. Total vegetable and total fruit consumption were not associated with pancreatic cancer risk (highest vs. lowest quintile, multivariable-adjusted hazard rate ratio = 1.23, 95% confidence interval: 0.86-1.75 and multivariable-adjusted hazard rate ratio = 0.90, 95% confidence interval: 0.66-1.24, respectively). Also, for cooked vegetables, raw vegetables and vegetables and fruits classified into subgroups, no associations were observed. Dietary carotenoids, vitamin C and E intake and supplements containing vitamin C or E were not associated with pancreatic cancer risk. The results were not modified by sex, smoking status and body mass index. In conclusion, we observed no association between a high consumption of vegetables and fruits and pancreatic cancer risk in this large cohort study, which is in agreement with previous prospective studies. Furthermore, we observed no association between the intake of carotenoids, vitamins and vitamin supplements and pancreatic cancer risk.

Obesity adversely affects survival in pancreatic cancer patients

BACKGROUND

Higher body-mass index (BMI) has been implicated as a risk factor for developing pancreatic cancer, but its effect on survival has not been thoroughly investigated. The authors assessed the association of BMI with survival in a sample of pancreatic cancer patients and used epidemiologic and clinical information to understand the contribution of diabetes and hyperglycemia.

METHODS

A survival analysis using Cox proportional hazards by usual adult BMI was performed on 1861 unselected patients with pancreatic adenocarcinoma; analyses were adjusted for covariates that included clinical stage, age, and sex. Secondary analyses incorporated self-reported diabetes and fasting blood glucose in the survival model.

RESULTS

BMI as a continuous variable was inversely associated with survival from pancreatic adenocarcinoma (hazard ratio [HR], 1.019 for each increased unit of BMI [kg/m2], P<.001) after adjustment for age, stage, and sex. In analysis by National Institutes of Health BMI category, BMIs of 30 to 34.99 kg/m2 (HR, 1.14; 95% confidence interval [CI], 0.98-1.33), 35 to 39.99 kg/m2 (HR 1.32, 95% CI 1.08-1.62), and ≥40 (HR 1.60, 95% CI 1.26-2.04) were associated with decreased survival compared with normal BMI of 18.5 to 24.99 kg/m2 (overall trend test P<.001). Fasting blood glucose and diabetes did not affect the results.

CONCLUSIONS

Higher BMI is associated with decreased survival in pancreatic cancer. Although the mechanism of this association remains undetermined, diabetes and hyperglycemia do not appear to account for the observed association.

Dietary factors and pancreatic cancer: the role of food bioactive compounds

Pancreatic cancer is the fourth leading cause of cancer mortality among both men and women in the United States with a 5-year survival rate of only 4%. Several dietary factors may influence the risk of developing pancreatic cancer and its recurrence. Some of these factors may offer innovative therapies for prevention of this disease. The goal of this review is to provide an overview of pancreatic cancer, as well as current knowledge on the epidemiological, in vitro, in vivo, and clinical studies conducted about this disease using various dietary agents. The main focus is on food-based approaches for preventing this disease particularly, citrus fruits, and foods containing flavonoids, curcumin, folate and vitamin D.

Diabetes and risk of pancreatic cancer: a pooled analysis of three large case-control studies

Racial differences in diabetes-associated pancreatic cancer (PC) and the interaction of diabetes with other risk factors are not well established. We determined the association between diabetes and risk of PC in 2,192 cases and 5,113 controls in three large case-control studies conducted at the National Cancer Institute, the University of California San Francisco, and the M.D. Anderson Cancer Center. In multivariable analyses, diabetes was associated with a 1.8-fold risk of PC [95% confidence interval (CI) = 1.5-2.1]. Risk estimates decreased with increasing years with diabetes (≤2 years OR = 2.9, 95% CI = 2.1-3.9; 3-5 years OR = 1.9, 95% CI = 1.3-2.6; 6-10 years OR = 1.6, 95% CI = 1.2-2.3; 11-15 years OR = 1.3, 95% CI = 0.9-2.0; > 15 years OR = 1.4, 95% CI = 1.0-2.0 (p for trend < 0.0001). Among diabetics, risk was higher in insulin ever users compared with nonusers (OR = 2.2, 95% CI = 1.6-3.7) and was restricted to insulin use of ≤3 years (OR = 2.4). Insulin use of >10 years was associated with a reduced risk of pancreatic cancer (OR = 0.5, 95% CI = 0.3-0.9; p for trend < 0.0001). Hispanic men and Asians had a higher risk of diabetes-associated PC than did whites and blacks, but the differences were not statistically significant. No significant interaction between diabetes and cigarette smoking, alcohol consumption and body mass index was observed. Although reverse causation may explain the association between diabetes diagnosed in close temporal proximity to PC, our results show that long-term diabetes, even though risk diminishes over time, remains a risk factor for PC independent of obesity and smoking.

Intake of fatty acids and antioxidants and pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area

There are no well-established modifiable risk factors for pancreatic cancer except smoking. Some dietary factors have been associated with pancreatic cancer risk and require further study. We examined the associations among intake of specific fatty acids and antioxidants and risk of pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area. Unconditional logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CI) as estimates of relative risk. Positive associations were observed for high levels of the 8 individual saturated fatty acids (4th vs. 1st quartile: ORs ranged from 1.6 to 2.6; all p(trend) < 0.01), monounsaturated palmitoleic and oleic fatty acids [OR = 1.6 (95% CI: 1.2-2.1) and 1.4 (95% CI: 1.1-1.9); both p(trend) < 0.01], and polyunsaturated linolenic acid [OR = 1.5 (95% CI: 1.1-2.0); p(trend) = 0.02]. Inverse associations were observed for high levels of gadolic acid [4th vs. 1st quartile: OR = 0.68 (95% CI: 0.50-0.92); p(trend) = 0.007] and omega-3 fatty acids [>or=0.85 g/day vs. 1st quartile: OR = 0.47 (95% CI: 0.25-0.90)]. An inverse association was also observed for high total intake of vitamin C [4th vs. 1st quartile: OR = 0.69 (95% CI: 0.51-0.94); p(trend) = 0.004] and of vitamin E [OR = 0.67 (95% CI: 0.49-0.92); p(trend) = 0.01]. Although similar decreased risks were also observed for high supplemental intake of these 2 vitamins (both p(trend) < 0.01), no association was observed for intake from food alone. These results support the hypotheses that a high intake of saturated and certain monounsaturated fatty acids may increase the risk of pancreatic cancer, whereas greater intake of omega-3 fatty acids, vitamins C and E may reduce the risk.

Consumption of food groups and the risk of pancreatic cancer: a case-control study

PURPOSE

The purpose of this study is to investigate whether the consumption of specific food groups predicts the risk of pancreatic cancer, a case-control study of nutrition and pancreatic cancer among French-Canadians was carried out in Montreal, Quebec, Canada.

METHODS

A total of 179 pancreatic cancer cases (97 males and 82 females) and 239 population-based control subjects were interviewed. Dietary intake was evaluated via a validated food frequency questionnaire that gathers information on over 200 different food items and beverages. Odd ratios (ORs) and 95% confidence intervals (CIs) were computed by unconditional logistic regression.

RESULTS

After adjustment for age, smoking, diabetes status, proxy interview, gender and total energy intake, a reduced risk of pancreatic cancer was related to vegetables and vegetable products [OR = 0.47; 95%CI: (0.21-1.06) p-trend = 0.024], while an increased risk was associated with the consumption of lamb, veal and game [OR = 2.24; 95%CI: (1.11-4.52) p-trend = 0.026], when the upper and lower quartiles of intake were compared. Changes in dietary intake over the last decade revealed an elevated risk with augmented consumption of soups, sauces and gravies [OR = 2.32; 95%CI: (1.20-4.49) p-trend=0.03], beef products [OR = 2.07; 95%CI: (0.95-4.51) p-trend=0.05] as well as fish and shellfish [OR = 1.48; 95%CI: (0.78-2.80) p-trend=0.05].

CONCLUSIONS

These findings suggest that a diet rich in vegetables and vegetable products may decrease the risk of pancreatic cancer.

Dietary intake of selected micronutrients and the risk of pancreatic cancer: an Italian case-control study

OBJECTIVE

several studies have shown an inverse relation between vegetable and fruit intake and pancreatic cancer, but no specific beneficial component of such foods has been consistently identified. We considered the role of 15 selected vitamins and carotenoids and 6 minerals on pancreatic cancer risk in an Italian case-control study.

METHODS

subjects were 326 patients with incident pancreatic cancer and 652 controls, admitted to the same hospitals as cases for acute conditions. Micronutrient computation was based on a validated and reproducible food-frequency questionnaire. We estimated the odds ratios (OR) and confidence intervals (CI) using conditional logistic regression models, adjusted for various confounding factors and for energy intake, according to the residual model.

RESULTS

comparing the highest to the lowest quintile of intake, the OR were 0.60 (95% CI 0.36-0.98) for vitamin E, 0.44 (95% CI 0.27-0.73) for vitamin C, 0.56 (95% CI 0.34-0.93) for folate, and 0.57 (95% CI 0.35-0.92) for potassium. No significant inverse associations were observed for α-carotene (OR = 0.69, 95% CI 0.43-1.12), β-carotene (OR = 0.64, 95% CI 0.39-1.06), and β-cryptoxanthin (OR = 0.66, 95% CI 0.39-1.09). No relation was found for other micronutrients considered.

CONCLUSION

our findings support a favorable role of vitamins E and C, selected carotenoids, and folate on pancreatic carcinogenesis.

Available carbohydrates, glycemic load, and pancreatic cancer: is there a link?

High-carbohydrate diets have been linked to pancreatic cancer risk in case-control studies, but prospective studies have shown mostly null results. The authors investigated the associations of glycemic load, glycemic index, and carbohydrate intake with pancreatic cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Dietary intake was assessed by using a self-administered questionnaire. Between 1998 and 2006 (median follow-up = 6.5 years), 266 incident, confirmed pancreatic cancers were identified among 109,175 participants. Hazards ratios and 95% confidence intervals were adjusted for sex, smoking, body mass index, and total energy. Overall, elevated risks for pancreatic cancer were observed in the 90th versus 10th percentile of glycemic load (hazards ratio (HR) = 1.45, 95% confidence interval (CI): 1.05, 2.00), available carbohydrate (HR = 1.47, 95% CI: 1.05, 2.06), and sucrose (HR = 1.37, 95% CI: 0.99, 1.89) intake. The positive association for available carbohydrate intake was observed during the first 4 years of follow-up (HR(<2 years) = 2.60, 95% CI: 1.34, 5.06; HR(2-<4 years) = 1.94, 95% CI: 1.06, 3.55) but not subsequently (HR = 0.86, 95% CI: 0.52, 1.44); the opposite pattern was observed for total fat and saturated fat intake. Rather than being causal, the short-term increase in pancreatic cancer risk associated with high available carbohydrate and low fat intake may be capturing dietary changes associated with subclinical disease.

Epidemiology of pancreatic cancer in Norway: trends in incidence, basis of diagnosis and survival 1965-2007

OBJECTIVE

Pancreatic cancer is the second most frequent gastrointestinal cancer in the Western world. Few reports on concomitant trends in pancreatic cancer incidence, diagnosis, mortality and survival exist at the national level. This study provides a baseline overview of the temporal patterns in these four indicators over the past four decades in Norway.

MATERIAL AND METHODS

We analysed trends in incidence, basis of diagnosis, relative survival and mortality from the Cancer Registry of Norway for the period 1965-2007.

RESULTS

Included were 21,663 patients with pancreatic cancers. Incidence and mortality rates remained at around 6-8 per 100,000 over the study period. Diagnoses based on clinical examination alone dropped from 12.5% (in the 1950s) to <1% (in the 2000s), while use of imaging techniques, such as CT and MRI, increased from 3.6% to >30%. Previously high rates of autopsy-verified diagnosis and non-therapeutic surgery decreased accordingly. Consistently more primary tumours (from 12.9% to 19.4%) and metastases (from 12.5% to 22.4%) had histological examination, and use of endoscopy increased to approximately 10%. Relative survival after diagnosis of pancreatic cancer remains very low. However, in recent years, a modest improvement in short-term survival has been noted, with 1-year survival rates of 18% and 16% for males and females, respectively.

CONCLUSIONS

The incidence and mortality for pancreatic cancer remain largely unchanged, with few 5-year survivors. Improved short-term survival may reflect more aggressive use of surgery and chemotherapy. Further elucidation of risk factors in pancreatic cancer is needed to enable effective prevention, early detection and improved treatment strategies.

Is sugar consumption detrimental to health? A review of the evidence 1995-2006

Many countries set quantitative targets for added sugars, justifying this by expressing concern about the likely impact of sugar on weight control, dental health, diet quality, or metabolic syndrome. This review considers whether current intakes of sugar are harmful to health, and analyses recent literature using a systematic approach to collate, rank, and evaluate published studies from 1995-2006. Results from high quality obesity studies did not suggest a positive association between body mass index and sugar intake. Some studies, specifically on sweetened beverages, highlighted a potential concern in relation to obesity risk, although these were limited by important methodological issues. Diet adequacy appeared to be achieved across sugar intakes of 6 to 20% energy, depending on subject age. Studies on metabolic syndrome reported no adverse effects of sugar in the long-term, even at intakes of 40-50% energy. The evidence for colorectal cancer suggested an association with sugar, but this appeared to have been confounded by energy intake and glycemic load. There was no credible evidence linking sugar with attention-deficit, dementia, or depression. Regarding dental caries, combinations of sugar amount/frequency, fluoride exposure, and food adhesiveness were more reliable predictors of caries risk than the amount of sugar alone. Overall, the available evidence did not support a single quantitative sugar guideline covering all health issues.

[Risk factors and early diagnosis of pancreatic cancer]

Pancreatic cancer (PC) is usually incurable. Identifying people at risk for developing PC may improve the prognosis of this entity. The main risk factors for PC are Peutz-Jeghers syndrome, hereditary pancreatitis and a history family of PC. Other factors, such as advanced age and smoking, should also be taken into account. PC screening is only useful in very high risk individuals. Tools that allow tumors to be identified in the early stages are required in order to apply appropriate curative treatments. In this scenario, only endoscopic ultrasound with cytological analysis of suspicious pancreatic lesions has proved to be useful.

Physical activity, diet, and pancreatic cancer: a population-based, case-control study in Minnesota

Although mounting evidence suggests that insulin resistance is involved in pancreatic carcinogenesis, few epidemiologic studies have comprehensively investigated the role of lifestyle factors influencing this metabolic disorder in the etiology of pancreatic cancer. We sought to examine this problem in a case-control study conducted in 1994-1998 in Minnesota. Cases (n = 186), aged 20 yr or older, were ascertained from all hospitals in the metropolitan area of the Twin Cities and the Mayo Clinic; from the latter, only cases residing in the Upper Midwest of the United States were recruited. Controls (n = 554) were randomly selected from the general population and frequency matched to cases by age (within 5 yr) and sex. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using unconditional logistic regression. After adjustment for confounders, physical activity was associated with a reduced risk, but this protective effect was confined to light activity and moderate activity only (OR = 0.55, 95% CI = 0.30-0.97, P(trend) = 0.038 and OR = 0.51, 95% CI = 0.28-0.93, P(trend) = 0.07, for highest vs. lowest quartile, respectively). An increased risk was found for dietary intakes of energy and fat but was statistically significant for saturated and polyunsaturated fat only. Of note, no appreciable difference in the magnitude of the associations existed between saturated, monounsaturated, and polyunsaturated fat. Compared with individuals in the lowest quartile of fiber intake, the risk was approximately halved for those in the third (OR = 0.49, 95% CI = 0.26-0.94) and the highest quartile (OR = 0.52, 95% CI = 0.21-1.30). Our study lends support to the hypothesis that dietary and other lifestyle factors influencing insulin resistance modulate pancreatic cancer risk.

Germ-line mutations, pancreatic inflammation, and pancreatic cancer

The fundamental problem underlying pancreatic cancer is altered genetics. Rare germ-line mutations lead to familial cancer syndromes that may include pancreatic cancer. But why do some people develop pancreatic cancer while others develop cancer in other organs, or not at all? We discuss the possibility that other common germ-line mutations diminish the ability of pancreatic cells to protect themselves from environmental or metabolic stressors, resulting in reactive molecules that lead to cell injury and DNA damage-with a series of lucky hits knocking out key tumor-suppressor genes and activating oncogenes in at least one cell with clonal growth potential. Inflammation likely accelerates this process, whether or not it is clinically evident. We also note the significant effects of smoking, alcohol, antioxidants, and diet on risk, and that together they confer a major portion of attributable risk that may be linked to the injury-inflammation-cancer pathway. Because we cannot change our genes, lifestyle choices are currently the best way to reduce pancreatic cancer risk until more effective preventative strategies are developed.

Macronutrients, fatty acids, cholesterol and pancreatic cancer

A role of diet and nutrition in pancreatic carcinogenesis has been suggested, but the association between selected macronutrients, fatty acids, cholesterol and pancreatic cancer remains controversial. We analysed data from a hospital-based case-control study conducted in Italy between 1991 and 2008, including 326 cases (174 men and 152 women) with incident pancreatic cancer, and 652 controls (348 men and 304 women) frequency-matched to cases by sex, age and study centre. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multiple logistic regression models conditioned on age, sex and study centre, and adjusted for year of interview, education, tobacco smoking, history of diabetes and energy intake. A positive association was found for animal proteins (OR=1.85 for the highest versus the lowest quintile of intake; 95% CI: 1.15-2.96; p for trend=0.039), whereas a negative association was observed for sugars (OR=0.52; 95% CI: 0.31-0.86; p for trend=0.003). Non-significant negative associations emerged for vegetable proteins (OR=0.69) and polyunsaturated fatty acids (OR=0.67). In conclusion, a diet poor in animal proteins and rich in sugars (mainly derived from fruit) appears to have a beneficial effect on pancreatic cancer risk.

Intake of folate, vitamins B6, B12 and methionine and risk of pancreatic cancer in a large population-based case-control study

OBJECTIVE

Folate and other methyl-group nutrients may play a key role in pancreatic carcinogenesis through their effects on DNA integrity. We examined the association between pancreatic cancer and intake of folate, vitamins B(6), B(12) and methionine in a large population-based case-control study.

METHODS

Risk factor data were collected during in-person interviews with 532 pancreatic cancer cases diagnosed in 1995-1999 and 1,701 frequency-matched controls in the San Francisco Bay Area. Dietary history and supplement use were obtained using a semi-quantitative food-frequency questionnaire developed at Harvard University. Adjusted unconditional logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI) as estimates of the relative risk.

RESULTS

Total folate intake was inversely associated with pancreatic cancer (5th vs. 1st quintile: OR = 0.67, 95% CI = 0.48-0.93, p (trend) = 0.04). Increased vitamin B(12) from food was positively associated with pancreatic cancer although risk estimates for quintiles 3-5 were similar (5th vs. 1st quintile: OR = 1.9, 95% CI = 1.3-2.6, p (trend) = 0.001). Intake of vitamin B(6) or methionine was not associated with pancreatic cancer risk.

CONCLUSIONS

Our study provided some support for an inverse association between folate intake and pancreatic cancer risk. The increased pancreatic cancer risk with vitamin B(12) intake from food warrants further investigation.

Dietary folate and folate vitamers and the risk of pancreatic cancer in the Netherlands cohort study

An association between high intake of folate and reduced risk of cancer has been suggested by previous research. However, epidemiologic data from cohort studies regarding the relationship between dietary folate and pancreatic cancer are sparse and inconsistent. We examined the association between dietary folate intake and risk of pancreatic cancer within the Netherlands Cohort Study on diet and cancer. Men and women (120,852), ages 55 to 69 years, were recruited. Information on diet was collected at baseline by means of food frequency questionnaires, and the cohort was followed for 13.3 years. Total folate and vitamer intake were calculated using folate contents of food items derived from a validated liquid chromatography trienzyme method. Cases (n = 363) were identified by record linkage with regional cancer registries and the Dutch National Database of Pathology Reports. A case-cohort approach was used using the follow-up data of a random subcohort (n = 5,000) identified at the onset of the cohort. Multivariable hazard ratios with 95% confidence intervals were estimated using Cox proportional hazards model. After adjusting for age, gender, smoking status, number of years smoked, number of cigarettes smoked per day, and intake of added sugar multivariate hazard ratio comparing the highest and lowest quintiles of folate intake for pancreatic cancer risk was 1.37 (confidence interval, 0.97-1.94; P(trend) = 0.07). When folate vitamers were analyzed separately, results did not show a difference in association. Our results do not support a protective association of total dietary folate or individual folate vitamers on the risk of pancreatic cancer.

Dietary fatty acids and pancreatic cancer in the NIH-AARP diet and health study

BACKGROUND

Previous research relating dietary fat, a modifiable risk factor, to pancreatic cancer has been inconclusive.

METHODS

We prospectively analyzed the association between intakes of fat, fat subtypes, and fat food sources and exocrine pancreatic cancer in the National Institutes of Health-AARP Diet and Health Study, a US cohort of 308 736 men and 216 737 women who completed a 124-item food frequency questionnaire in 1995-1996. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models, with adjustment for energy intake, smoking history, body mass index, and diabetes. Statistical tests were two-sided.

RESULTS

Over an average follow-up of 6.3 years, 865 men and 472 women were diagnosed with exocrine pancreatic cancer (45.0 and 34.5 cases per 100 000 person-years, respectively). After multivariable adjustment and combination of data for men and women, pancreatic cancer risk was directly related to the intakes of total fat (highest vs lowest quintile, 46.8 vs 33.2 cases per 100 000 person-years, HR = 1.23, 95% CI = 1.03 to 1.46; P(trend) = .03), saturated fat (51.5 vs 33.1 cases per 100 000 person-years, HR = 1.36, 95% CI = 1.14 to 1.62; P(trend) < .001), and monounsaturated fat (46.2 vs 32.9 cases per 100 000 person-years, HR = 1.22, 95% CI = 1.02 to 1.46; P(trend) = .05) but not polyunsaturated fat. The associations were strongest for saturated fat from animal food sources (52.0 vs 32.2 cases per 100 000 person-years, HR = 1.43, 95% CI = 1.20 to 1.70; P(trend) < .001); specifically, intakes from red meat and dairy products were both statistically significantly associated with increased pancreatic cancer risk (HR = 1.27 and 1.19, respectively).

CONCLUSION

In this large prospective cohort with a wide range of intakes, dietary fat of animal origin was associated with increased pancreatic cancer risk.

Body mass index and risk, age of onset, and survival in patients with pancreatic cancer

CONTEXT

Obesity has been implicated as a risk factor for pancreatic cancer.

OBJECTIVE

To demonstrate the association of excess body weight across an age cohort and the risk, age of onset, and overall survival of patients with pancreatic cancer.

DESIGN, SETTING, AND PARTICIPANTS

A case-control study of 841 patients with pancreatic adenocarcinoma and 754 healthy individuals frequency matched by age, race, and sex. The study was conducted at a university cancer center in the United States from 2004 to 2008. Height and body weight histories were collected by personal interview starting at ages 14 to 19 years and over 10-year intervals progressing to the year prior to recruitment in the study.

MAIN OUTCOME MEASURES

The associations between patients' body mass index (BMI) and risk of pancreatic cancer, age at onset, and overall survival were examined by unconditional logistic regression, linear regression, and Cox proportional hazard regression models, respectively.

RESULTS

Individuals who were overweight (a BMI of 25-29.9) from the ages of 14 to 39 years (highest odds ratio [OR], 1.67; 95% confidence interval [CI], 1.20-2.34) or obese (a BMI > or = 30) from the ages of 20 to 49 years (highest OR, 2.58; 95% CI, 1.70-3.90) had an associated increased risk of pancreatic cancer, independent of diabetes status. The association was stronger in men (adjusted OR, 1.80; 95% CI, 1.45-2.23) by mean BMI from the ages of 14 to 59 years than in women (adjusted OR, 1.32; 95% CI, 1.02-1.70) and in ever smokers (adjusted OR, 1.75; 95% CI, 1.37-2.22) than in never smokers (adjusted OR, 1.46; 95% CI, 1.16-1.84). The population-attributable risk percentage of pancreatic cancer based on the mean BMI from the ages of 14 to 59 years was 10.3% for never smokers and 21.3% for ever smokers. Individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years (median age of onset was 64 years for patients with normal weight, 61 years for overweight patients [P = .02], and 59 years for obese patients [P < .001]). Compared with those with normal body weight and after adjusting for all clinical factors, individuals who were overweight or obese from the ages of 30 to 79 years or in the year prior to recruitment had reduced overall survival of pancreatic cancer regardless of disease stage and tumor resection status (overweight patients: hazard ratio, 1.26 [95% CI, 0.94-1.69], P = .04; obese patients: hazard ratio, 1.86 [95% CI, 1.35-2.56], P < .001).

CONCLUSIONS

Overweight or obesity during early adulthood was associated with a greater risk of pancreatic cancer and a younger age of disease onset. Obesity at an older age was associated with a lower overall survival in patients with pancreatic cancer.

Medical management of pancreatic adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in the United States. In 2008, an estimated 34,290 people died from pancreatic cancer and 37,680 new cases were diagnosed. Despite modern treatment, 90% of patients die within 1 year of diagnosis. Pancreatectomy is still the only potentially curative approach, but most patients have incurable disease by the time they are diagnosed, and fewer than 20% are candidates for surgery. In the present paper the English-language literature addressing the medical management in pancreatic cancer was reviewed. Based on these data we will discuss the role of currently used chemotherapy and target therapy in pancreatic cancer, as well as perspectives of the emerging strategies that are arising in order to improve the outcomes of this complex disease.

Glycemic index, carbohydrates, glycemic load, and the risk of pancreatic cancer in a prospective cohort study

Diets with high glycemic index and glycemic load have been associated with insulin resistance. Insulin resistance has been implicated in the etiology of pancreatic cancer. We prospectively investigated the associations between glycemic index, carbohydrates, glycemic load, and available carbohydrates dietary constituents (starch and simple sugar) intake and the risk of pancreatic cancer. We followed the participants in the NIH-AARP Diet and Health Study from 1995/1996 through December 2003. A baseline self-administered food frequency questionnaire was used to assess the dietary intake and exposure information. A total of 1,151 exocrine pancreatic cancer cases were identified from 482,362 participants after excluding first-year of follow-up. We used multivariate Cox proportional hazards regression models to calculate relative risks (RR) and 95% confidence intervals (95% CI) for pancreatic cancer. There were no associations between glycemic index, total or available carbohydrates, gycemic load, and pancreatic cancer risk. Participants with high free fructose and glucose intake were at a greater risk of developing pancreatic cancer (highest compared with lowest quintile, RR, 1.29; 95% CI, 1.04-1.59; P trend = 0.004 and RR, 1.35; 95% CI, 1.10-1.67; P trend = 0.005, respectively). There were no statistically significant interactions by body mass index, physical activity, or smoking status. Our results do not support an association between glycemic index, total or available carbohydrate intake, and glycemic load and pancreatic cancer risk. The higher risk associated with high free fructose intake needs further confirmation and elucidation.

Pancreatic steatosis promotes dissemination and lethality of pancreatic cancer

BACKGROUND

Obesity is a worldwide epidemic. Clinical and basic studies have shown obesity to be associated with an increased incidence and progression of pancreatic cancer. The precise role that pancreatic fat plays in this process has remained undefined. We tested the hypothesis that pancreatic steatosis would be associated with increased dissemination and reduced survival in patients with resected pancreatic cancer.

STUDY DESIGN

A case-control analysis was conducted in patients who had undergone resection for pancreatic adenocarcinoma. Twenty lymph node-positive patients and 20 node-negative patients were matched for age (59 versus 63 years), gender (70% male versus 60% male), body mass index (24.5 versus 25.6), medical comorbidities (hypertension, diabetes, hyperlipidemia), tumor size (2.8 versus 2.6 cm), and resection status (Ro 80% versus 85%). Pancreatic neck margins were reviewed in a blinded fashion by two trained investigators. Pancreatic fat (number of cells/5 high power field) and degree of fibrosis (0 to 4+) were recorded.

RESULTS

Node-positive patients had significantly more fat cells in the pancreas compared with node-negative patients (46.4 +/- 8.7 versus 21.4 +/- 4.8; p < 0.02). Node-positive patients also demonstrated decreased fibrosis compared with node-negative patients (1.7 +/- 0.3 versus 2.7 +/- 0.3; p < 0.02). Mean survival was reduced in node-positive patients (18.9 +/- 2.7 versus 30.8 +/- 4.8 months; p < 0.04).

CONCLUSIONS

These data show that increased pancreatic fat promotes dissemination and lethality of pancreatic cancer. We conclude that pancreatic steatosis alters the tumor microenvironment, enhances tumor spread, and contributes to the early demise of patients with pancreatic adenocarcinoma.

Sweets, sweetened beverages, and risk of pancreatic cancer in a large population-based case-control study

OBJECTIVE

We examined the associations between sweets, sweetened and unsweetened beverages, and sugars and pancreatic cancer risk.

METHODS

We conducted a population-based case-control study (532 cases, 1,701 controls) and used multivariate logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI). Because associations were often different by sex, we present results for men and women combined and separately.

RESULTS

Among men, greater intakes of total and specific sweets were associated with pancreatic cancer risk (total sweets: OR = 1.9, 95% CI: 1.0, 3.6; sweet condiments: OR = 1.9, 95% CI: 1.2, 3.1; chocolate candy: OR = 2.4, 95% CI: 1.1, 5.0; other mixed candy bars: OR = 3.3, 95% CI: 1.5, 7.3 for 1 + servings/day versus none/rarely). Sweets were not consistently associated with risk among women. Sweetened beverages were not associated with increased pancreatic cancer risk. In contrast, low-calorie soft drinks were associated with increased risk among men only; while other low-/non-caloric beverages (e.g., coffee, tea, and water) were unassociated with risk. Of the three sugars assessed (lactose, fructose, and sucrose), only the milk sugar lactose was associated with pancreatic cancer risk (OR = 2.0, 95% CI: 1.5, 2.7 comparing extreme quartiles).

CONCLUSION

These results provide limited support for the hypothesis that sweets or sugars increase pancreatic cancer risk.

Citrus fruit intake and pancreatic cancer risk: a quantitative systematic review

OBJECTIVES

The purpose of this systematic review was to investigate the association between dietary intake of citrus fruits and pancreatic cancer risk.

METHODS

Authors searched electronic databases and the reference lists of publications of studies addressing diet and pancreatic cancer up to December 2007. All of the epidemiological studies that obtained individual data on dietary intake of citrus fruits and presented risk estimates of the association between intake of citrus fruits and risk of pancreatic cancer were identified and included. Using general variance-based methods, study-specific odds ratios (ORs)/relative risk and associated confidence interval (CI)/SE for highest versus lowest intake of citrus fruits level were extracted from each article.

RESULTS

Nine articles including 4 case-control studies and 5 cohort studies proved eligible. Overall summary OR using random effect model suggested an inverse association in risk of pancreatic cancer with intake of citrus fruits (summary OR, 0.83; 95% CI, 0.70-0.98) with large heterogeneity across studies (I = 49.9%).

CONCLUSIONS

Pooled results from observational studies showed an inverse association between intake of citrus fruits and the risk of pancreatic cancer, although results vary substantially across studies, and the apparent effect is restricted to the weaker study design (case-control studies).

Pancreatic cancer screening: state of the art

Pancreatic cancer is a devastating disease with a median survival of approximately 6 months after diagnosis. Many factors are associated with a worse outcome; examples include late diagnosis, low resection rate, aggressive tumor behavior and a lack of an effective chemotherapy regimen. Owing to the low prevalence of pancreatic cancer relative to the diagnostic accuracy of present detection methods and the absence of promising treatment modalities, even in early stages, it is currently neither advisable nor cost effective to screen the general population. Efforts are focused on early screening of selected high-risk-cohorts, who account for approximately 10% of patients with pancreatic cancer. These include patients with chronic pancreatitis, individuals with a family history of pancreatic cancer, patients with hereditary pancreatitis, Peutz-Jeghers syndrome, cystic fibrosis or familial atypical multiple mole melanoma. At present, a multimodal-screening approach of endoscopic ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography appears to be the most effective method to screen for pancreatic cancer in high-risk patients. Continued efforts are needed to elucidate effective testing to identify patients with nonhereditary risk factors who will benefit from screening protocols. A combined approach of serum markers, genetic markers and specific imaging studies may prove to be the future of pancreatic screening.

Energy balance, physical activity, and cancer risk

This chapter posits that cancer is a complex and multifactorial process as demonstrated by the expression and production of key endocrine and steroid hormones that intermesh with lifestyle factors (physical activity, body size, and diet) in combination to heighten cancer risk. Excess weight has been associated with increased mortality from all cancers combined and for cancers of several specific sites. The prevalence of obesity has reached epidemic levels in many parts of the world; more than 1 billion adults are overweight with a body mass index (BMI) exceeding 25. Overweight and obesity are clinically defined indicators of a disease process characterized by the accumulation of body fat due to an excess of energy intake (nutritional intake) relative to energy expenditure (physical activity). When energy intake exceeds energy expenditure over a prolonged period of time, the result is a positive energy balance (PEB), which leads to the development of obesity. This physical state is ideal for intervention and can be modulated by changes in energy intake, expenditure, or both. Nutritional intake is a modifiable factor in the energy balance-cancer linkage primarily tested by caloric restriction studies in animals and the effect of energy availability. Restriction of calories by 10 to 40% has been shown to decrease cell proliferation, increasing apoptosis through anti-angiogenic processes. The potent anticancer effect of caloric restriction is clear, but caloric restriction alone is not generally considered to be a feasible strategy for cancer prevention in humans. Identification and development of preventive strategies that "mimic" the anticancer effects of low energy intake are desirable. The independent effect of energy intake on cancer risk has been difficult to estimate because body size and physical activity are strong determinants of total energy expenditure. The mechanisms that account for the inhibitory effects of physical activity on the carcinogenic process are reduction in fat stores, activity related changes in sex-hormone levels, altered immune function, effects in insulin and insulin-like growth factors, reduced free radical generation, and direct effect on the tumor. Epidemiologic evidence posits that the cascade of actions linking overweight and obesity to carcinogenesis are triggered by the endocrine and metabolic system. Perturbations to these systems result in the alterations in the levels of bioavailable growth factors, steroid hormones, and inflammatory markers. Elevated serum concentrations of insulin lead to a state of hyperinsulinemia. This physiological state causes a reduction in insulin-like growth factor-binding proteins and promotes the synthesis and biological activity of insulin-like growth factor (IGF)-I, which regulates cellular growth in response to available energy and nutrients from diet and body reserves. In vitro studies have clearly established that both insulin and IGF-I act as growth factors that promote cell proliferation and inhibit apoptosis. Insulin also affects on the synthesis and biological availability of the male and female sex steroids, including androgens, progesterone, and estrogens. Experimental and clinical evidence also indicates a central role of estrogens and progesterone in regulating cellular differentiation, proliferation, and apoptosis induction. Hyperinsulinemia is also associated with alterations in molecular systems such as endogenous hormones and adipokines that regulate inflammatory responses. Obesity-related dysregulation of adipokines has the ability to contribute to tumorigenesis and tumor invasion via metastatic potential. Given the substantial level of weight gain in industrialized countries in the last two decades, there is great interest in understanding all of the mechanisms by which obesity contributes to the carcinogenic process. Continued focus must be directed to understanding the various relationships between specific nutrients and dietary components and cancer cause and prevention. A reductionist approach is not sufficient for the basic biological mechanisms underlying the effect of diet and physical activity on cancer. The joint association between energy balance and cancer risk are hypothesized to share the same underlying mechanisms, the amplification of chemical mediators that modulate cancer risk depending on the responsiveness to those hormones to the target tissue of interest. Disentangling the connection between obesity, the insulin-IGF axis, endogenous hormones, inflammatory markers, and their molecular interaction is vital.

Vitamin E delta-tocotrienol levels in tumor and pancreatic tissue of mice after oral administration

Tocotrienols are natural vitamin E compounds that are known to have a neuroprotective effect at nanomolar concentration and anti-carcinogenic effect at micromolar concentration. In this report, we investigated the pharmacokinetics, tumor and pancreatic tissue levels, and toxicity of delta-tocotrienol in mice because of its anti-tumor activity against pancreatic cancer. Following a single oral administration of delta-tocotrienol at 100 mg/kg, the peak plasma concentration (C(max)) was 57 +/- 5 micromol/l, the time required to reach peak plasma concentration (T(max)) was 2 h and plasma half-life (t(1/2)) was 3.5 h. The delta-tocotrienol was cleared from plasma and liver within 24 h, but delayed from the pancreas. When mice were fed delta-tocotrienol for 6 weeks, the concentration in tumor tissue was 41 +/- 3.5 nmol/g. This concentration was observed with the oral dose (100 mg/kg) of delta-tocotrienol which inhibited tumor growth by 80% in our previous studies. Interestingly, delta-tocotrienol was 10-fold more concentrated in the pancreas than in the tumor. We observed no toxicity due to delta-tocotrienol as mice gained normal weight with no histopathological changes in tissues. Our data suggest that bioactive levels of delta-tocotrienol can be achieved in the pancreas following oral administration and supports its clinical investigation in pancreatic cancer.

Predictors of fasting serum insulin and glucose and the risk of pancreatic cancer in smokers

OBJECTIVES

A history of type 2 diabetes is one of few consistent risk factors for pancreatic cancer. Potentially modifiable factors related to fasting insulin and glucose concentrations may influence pancreatic cancer risk.

METHODS

Multiple linear regression models were used to identify anthropometric, clinical, behavioral, and dietary factors associated with fasting insulin and glucose in a subcohort of non-diabetics in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (n = 366). Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated among the larger cohort (n = 27,035).

RESULTS

During follow-up (median 16.1 years), 305 participants developed pancreatic cancer. Fasting insulin and/or glucose were positively associated with body mass index (BMI), height, and dietary total and saturated fat and inversely associated with serum high-density lipoprotein cholesterol (HDL) and dietary available carbohydrates, sucrose, and alcohol. Comparing highest to lowest quintiles, total fat (HR = 1.54, 95% CI 1.05-2.25, p-trend = 0.01) and saturated fat (HR = 1.38, 95% CI 0.97-1.98, p-trend = 0.06) were positively associated and available carbohydrates (HR = 0.63, 95% CI 0.44-0.90, p-trend = 0.01), particularly sucrose (HR = 0.62, 95% CI 0.43-0.89, p-trend = 0.09), were inversely associated with risk of pancreatic cancer. BMI, HDL, height, and alcohol were not associated with pancreatic cancer risk.

CONCLUSION

Dietary fat is associated with higher fasting insulin concentrations and may increase pancreatic cancer risk in smokers.

Coffee consumption and the risk of cancer: an overview

Habitual coffee drinking has been associated with a reduced risk of mortality and chronic diseases, including cancer. The favourable influence of coffee is supported by several plausible mechanisms due to the presence of a variety of biological compounds such as caffeine, diterpenes, caffeic acid, polyphenols as well as volatile aroma and heterocyclic substances. Current evidence suggests that coffee consumption is associated with a reduced risk of liver, kidney, and to a lesser extent, premenopausal breast and colorectal cancers, while it is unrelated to prostate, pancreas and ovary cancers. Coffee drinking may still help reduce death due to liver cancer.

Obesity surgery and malignancy: our experience after 1500 cases

BACKGROUND

Obesity is a risk factor for cancer and is associated with increased mortality from a number of malignancies. We describe our experience with bariatric surgery patients with a history of malignancy and review the safety and outcomes of bariatric surgery in patients with a history of cancer.

METHODS

We performed a retrospective review of prospectively collected data from all patients diagnosed with a malignancy before, during, or after bariatric surgery. Data on weight loss, co-morbidities, and recurrence were collected.

RESULTS

From July 1999 to February 2008, 1566 patients underwent bariatric surgery. Of these 1566 patients, 36 (2.3%) had a history of malignancy before they underwent bariatric evaluation and surgery, 4 (0.26%) were diagnosed with a malignancy during their preoperative evaluation, 2 of whom subsequently underwent bariatric surgery, and 2 had intraoperative findings suspicious for malignancy; bariatric surgery was completed in both cases. The evaluation revealed renal cell carcinoma and low-grade lymphoma, respectively. No procedures were aborted because of a suspicion of malignancy. Postoperatively, 16 patients (0.9%) were diagnosed with cancer, 3 of whom had a history of malignancy: 1 with metastatic renal cell, 1 with recurrent melanoma, and 1, who had had prostate cancer, with bladder cancer.

CONCLUSION

A history of malignancy does not appear to be a contraindication for bariatric surgery as long as the life expectancy is reasonable. Screening for bariatric surgery might reveal the malignancy. Bariatric surgery does not seem to have a negative effect on the treatment of malignancies that are discovered in the postoperative period.